A P2P Grid Services-Based Protocol: Design and Evaluation

Abstract

Several aspects of today’s Grids are based on centralized or hierarchical services. However, as Grid sizes increase from tens to thousands of hosts, functionalities should be decentralized to avoid bottlenecks and guarantee scalability. A way to ensure Grid scalability is to adopt Peer-to-Peer (P2P) models and techniques to implement nonhierarchical decentralized Grid services and systems. Standard P2P protocols based on a pervasive exchange of messages, such as Gnutella, appear to be inadequate for OGSA Grids, where peers communicate among them through Grid Services mechanisms. This paper proposes a modified Gnutella discovery protocol, named Gridnut, which makes it suitable for OGSA Grids. In particular, Gridnut uses appropriate message buffering and merging techniques to make Grid Services effective as a way to exchange messages in a P2P fashion. We present the design of Gridnut, and compare Gnutella and Gridnut performances under different network and load conditions.